Roll-to-roll vacuum deposition apparatus

ABSTRACT

[Object] To provide a roll-to-roll vacuum deposition apparatus capable of easily and speedily adjusting a pressing force between a printing roller and a backup roller. 
     [Solving Means] In the present invention, by adjusting a pressing force between a printing roller and a backup roller through a relative movement of a mask forming unit including the printing roller and a transfer roller with respect to a vacuum chamber, individual adjustments of the printing roller and the transfer roller are eliminated and an adjustment of a pressing force on a unit basis is realized, thus achieving simplification of a structure, simplification and enhancement in precision of tasks, and a reduction in work time.

FIELD

The present invention relates to a roll-to-roll vacuum depositionapparatus favorably used in producing, for example, aself-protection-function-type film capacitor.

BACKGROUND

From the past, a roll-to-roll vacuum vapor deposition apparatus thatdeposits, while paying out an insulation film such as a plastic filmfrom a payout roller, a metal layer onto a surface of the film andtaking up the film by a take-up roller thereafter is used in producing afilm capacitor.

Incidentally, the film capacitor of this type includes aself-protection-function type in which a metal deposition layer formedon a surface of a film is fragmented into a plurality of capacitorpieces, and the adjacent capacitor pieces are mutually connected at ajunction portion that is formed of the same deposition layer and has anarrow width. In the film capacitor of this type, the junction portionis fused when an insulation breakdown occurs in a part of the filmcapacitor (fuse function) so that an insulation breakdown area of thecapacitor is suppressed at minimum on an individual piece basis.

When producing such a self-protection-type film capacitor by theroll-to-roll vacuum vapor deposition apparatus described above, a maskforming means for forming a mask pattern that defines a deposition areaof the metal layer with respect to a deposition surface of the film isinterposed between the payout roller and an evaporation source (see, forexample, Patent Document 1 below).

As the mask forming means, while nipping the film between a printingroller (plate cylinder) and a backup roller (impression cylinder) andconveying it, an oil for forming a mask pattern that has beentransferred onto the printing roller from an oil supply source via atransfer roller is successively transferred onto the deposition surfaceof the film from the printing roller. Accordingly,self-protection-function-type film capacitors each having a capacitorpiece in an arbitrary shape are produced successively.

Meanwhile, in a roll-to-roll vacuum vapor deposition apparatus of therelated art, the printing roller and the transfer roller have beenprovided to a member fixed in the vacuum chamber. Further, such a rollergroup has been adjusted in the atmosphere, and the vacuum chamber hasbeen exhausted thereafter.

However, the vacuum chamber is deformed to some extent when a pressureinside is reduced. In particular, recent vacuum chambers are increasedin size, with a tendency that a deformation amount of the vacuum chamberat a time of exhaustion increases. A positional accuracy of a maskforming unit is required to be 1/100 mm or less, but a deformation ofthe vacuum chamber may be caused in an order of about 1 mm. Therefore,even when the roller group of the mask forming unit is adjusted in theatmosphere, the influence of the deformation may affect patternformation. Thus, it has been necessary to adjust the roller group inconsideration of the deformation amount and repeatedly perform theadjustment in the atmosphere and a post-exhaustion check, thus resultingin an increase in the number of processes.

Patent Document 1: Japanese Patent Application Laid-open No. Hei10-81958

SUMMARY Problems to be Solved by the Invention

In forming a mask pattern by the mask forming means described above, apressing force balance between the printing roller and the backup rollerin the film width direction becomes important. When the balance of thepressing force between those rollers is poor, transfer accuracy on oneend side and that on the other end side regarding the film widthdirection become different, to thus induce a transfer failure such aspattern breakage in some cases.

In this regard, Patent Document 1 above discloses a method involvingproviding a press-driving means to each of the printing roller and thetransfer roller constituting the mask forming means, and individuallyadjusting the pressing force between the transfer roller and theprinting roller and that between the printing roller and the backuproller.

By the method of individually adjusting the pressing fore between theprinting roller and the transfer roller, however, there is a problemthat a task becomes complex and the work time is elongated. There isalso a problem that a structure of the mask forming means becomescomplex.

The present invention has been made in view of the above-mentionedproblems, and therefore has an object to provide a roll-to-roll vacuumdeposition apparatus capable of easily and speedily adjusting a pressingforce balance between a printing roller and a backup roller.

Means for Solving the Problems

To solve the problems above, a roll-to-roll vacuum deposition apparatusaccording to the present invention is characterized in that a maskforming means for forming a mask pattern that defines a deposition areaof a deposition material on a deposition surface of a film includes amask forming unit including a supply source for an oil for forming themask pattern, a first roller for holding the oil supplied from thesupply source at an outer circumference, and a second roller fortransferring the oil onto the deposition surface of the film as the maskpattern, a backup roller for nipping the film with the second roller andcausing the film to come into pressure-contact with the second roller,and a unit moving mechanism for moving the mask forming unit withrespect to a vacuum chamber; and the unit moving mechanism moves aposition of the mask forming unit with respect to the backup roller andadjusts a balance of a pressure contact force between the second rollerand the backup roller in a width direction of the film.

In the present invention, the second roller corresponds to the printingroller. By adjusting the pressing force balance between the secondroller and the backup roller in the film width direction through therelative movement of the mask forming unit including the first rollerand the second roller with respect to the vacuum chamber, individualadjustments of the first roller and the second roller are eliminated andan adjustment of the pressing force balance on a unit basis is realized,thus achieving simplification of tasks and a reduction in work time.

Moreover, in the present invention, the mask forming unit includes aframe for supporting both ends of a shaft of the first roller and bothends of a shaft of the second roller, the frame is movably disposed on apedestal fixed to the vacuum chamber, and the unit moving mechanismmoves at least one end of the frame in a direction of the backup roller.Accordingly, the structure can be simplified, and it also becomespossible to easily and speedily adjust the pressing force balancebetween the second roller and the backup roller in the film widthdirection while enabling an adjustment of parallelism of the shaft ofthe second roller with respect to the backup roller. Preferably, theframe is capable of moving rotationally about a point on the pedestal.

Furthermore, because the unit moving mechanism can be operated remotelyfrom outside the vacuum chamber, an adjustment of the mask forming unitafter exhaustion can also be carried out with ease.

Effect of the Invention

According to the roll-to-roll vacuum deposition apparatus of the presentinvention, a pressing force balance between the printing roller and thebackup roller can be easily and speedily adjusted.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic structural diagram of a roll-to-roll vacuum vapordeposition apparatus as a roll-to-roll vacuum deposition apparatusaccording to an embodiment of the present invention;

FIG. 2 are diagrams each showing an example of a mask pattern formed bya mask forming unit in the roll-to-roll vacuum vapor depositionapparatus shown in FIG. 1, in which FIG. 2A shows a state prior todeposition of a metal layer, and FIG. 2B shows a state after thedeposition;

FIG. 3 is a schematic side view of the mask forming unit of theroll-to-roll vacuum vapor deposition apparatus shown in FIG. 1; and

FIG. 4 are diagrams showing a structure of the mask forming unit shownin FIG. 3, in which FIG. 4A is a side view and FIG. 4B is a plan viewthereof.

DETAILED DESCRIPTION

Hereinafter, an embodiment of the present invention will be describedwith reference to the drawings. In this embodiment, descriptions will begiven on an example where the present invention is applied to aroll-to-roll vacuum vapor deposition apparatus as a roll-to-roll vacuumdeposition apparatus.

FIG. 1 is a schematic structural diagram of a roll-to-roll(take-up-type) vacuum vapor deposition apparatus 10 according to theembodiment of the present invention. The roll-to-roll vacuum vapordeposition apparatus 10 of this embodiment includes a vacuum chamber 11,a payout roller 13 for a film 12, a cooling can roller 14, a take-uproller 15 for the film 12, and an evaporation source (corresponding to a“depositing means” of the present invention) 16 of an evaporationmaterial.

The vacuum chamber 11 is connected to a vacuum exhaust system such as avacuum pump (not shown) via a pipe connection portion 11 a, and isexhausted to reduce a pressure inside to a predetermined vacuum degree.An internal space of the vacuum chamber 11 is sectioned by a partitionplate 11 b into a room in which the payout roller 13, the take-up roller15, and the like are disposed, and a room in which the evaporationsource 16 is disposed.

The film 12 is constituted of a long plastic film having an insulationproperty and cut at a predetermined width. For example, an OPP (orientedpolypropylene) film, a PET (polyethylene terephthalate) film, or a PPS(polyphenylene sulfide) film is used. The film 12 is paid out from thepayout roller 13 and is taken up by the take-up roller 15 via aplurality of guide rollers and the can roller 14. It should be notedthat although not shown, each of the payout roller 13 and the take-uproller 15 is provided with a rotary drive portion.

The can roller 14 is tubular and made of metal such as iron. Inside, thecan roller 14 has a cooling mechanism such as a cooling mediumcirculation system, a rotary drive mechanism for rotationally drivingthe can roller 14, and the like. The film 12 is wound around acircumferential surface of the can roller 14 at a predetermined holdingangle. The film 12 wound around the can roller 14 is deposited with, ona deposition surface on an outer surface side thereof, an evaporationmaterial from the evaporation source 16 so as to form a deposited layer,and at the same time, is cooled by the can roller 14.

The payout roller 13, the can roller 14, the take-up roller 15, and theother guide rollers above constitute a “traveling means” of the presentinvention for causing the film 12 to travel inside the vacuum chamber11.

The evaporation source 16 accommodates the evaporation material and hasa mechanism for causing the evaporation material to evaporate by heatingusing a well-known technique such as resistance heating, inductionheating, and electron beam heating. The evaporation source 16 isdisposed below the can roller 14 and causes the vapor of the evaporationmaterial to adhere onto the film 12 on the can roller 14 opposedthereto, to thus form a deposited layer. It should be noted that theevaporation source 16 corresponds to a “depositing means” of the presentinvention for depositing a deposition material onto the traveling film12.

As the evaporation material, in addition to a metal element single bodysuch as Al (aluminum), Co (cobalt), Cu (copper), Ni (nickel), and Ti(titanium), two or more metals such as Al—Zn (zinc), Cu—Zn, and Fe(iron)-Co, or a multi-component alloy is applicable. In addition, thenumber of evaporation source 16 is not limited to one, and a pluralityof evaporation sources may be provided.

The roll-to-roll vacuum vapor deposition apparatus 10 of this embodimentadditionally includes a mask forming unit 20. The mask forming unit 20is disposed upstream of the evaporation source 16, that is, between thepayout roller 13 and the evaporation source 16 (can roller 14). The maskforming unit 20 constitutes a “mask forming means” of the presentinvention together with a backup roller 21 to be described later.

FIG. 2 each show the deposition surface of the film 12. The mask formingunit 20 is structured so that a mask pattern (oil pattern) 25 in a formindicated by the hatching in FIG. 2A, for example, is applied ontoalmost the entire surface of the deposition surface of the film 12.Because a metal layer is not deposited on the mask pattern 25, after thedeposition, a metal layer 26 in a form in whichsubstantially-rectangular metal patterns obtained by depositing theevaporation material onto openings 25 a of the mask pattern 25 areconnected at a predetermined pitch via junction portions 26 a isdeposited. It should be noted that the form in which the metal layer 26is deposited is not limited to that described above.

It should be noted that each of the metal patterns constitutes acapacitor piece and functions as a self-protection-function-type filmcapacitor in which the junction portion 26 a is fused when an insulationbreakdown occurs in a part of the film capacitor so that an insulationbreakdown area of the capacitor is suppressed at minimum on anindividual piece basis.

FIG. 3 is a schematic structural diagram of the mask forming unit 20.The mask forming unit 20 includes an oil injection source 31A, an oilsupply roller 31 such as an Anilox roller, a transfer roller (firstroller) 32 for holding the oil supplied from the oil supply roller 31 atan outer circumference, and a printing roller (second roller) 33 ontowhich the oil is transferred from the transfer roller 32 and thattransfers the oil onto the deposition surface of the film 12 as the maskpattern 25. It should be noted that the oil injection source 31A and theoil supply roller 31 constitute a “supply source for an oil” of thepresent invention. It should also be noted that the oil supply sourcemay be constituted only of the oil injection source 31A.

The transfer roller 32 is supplied with a predetermined amount of oilfrom the oil supply roller 31, and transfers the supplied oil onto theprinting roller 33. A convex plate corresponding to the mask pattern 25is formed on a surface of the printing roller 33, and the oiltransferred onto the convex plate is transferred onto the depositionsurface of the film 12 so as to form the mask pattern 25. The printingroller 33 has a shaft length longer than a width dimension of the film12.

The oil injection source 31A and both ends of the shaft of each of theoil supply roller 31, the transfer roller 32, and the printing roller 33are supported by a common frame body 34. Further, although not shown,the frame body 34 is provided with a driving unit for rotationallydriving the oil supply roller 31, the transfer roller 32, and theprinting roller 33. The frame body 34 constitutes a bottom portion andwall portions on both sides of the mask forming unit 20, and the bottomportion of the frame body 34 is disposed on a pedestal 18 attached on apart of an inner wall surface of the vacuum chamber 11 via a unit movingmechanism 51 to be described later.

Meanwhile, the backup roller 21 nips the film 12 with the printingroller 33 and causes the film 12 to come into pressure-contact with theprinting roller 33. The backup roller 21 is provided with a biasingmechanism 41 for biasing the backup roller 21 toward the printing roller33. The biasing mechanism 41 includes a biasing tool 42 for supportingboth ends of a shaft portion of the backup roller 21 and a driving motor43 for biasing the biasing tool 42 toward the printing roller 33. Itshould be noted that the backup roller 21 is attached swingably to apart of the vacuum chamber 11 via a supporting arm 44.

The roll-to-roll vacuum vapor deposition apparatus 10 of this embodimentincludes a unit moving mechanism 51 for relatively moving the maskforming unit 20 with respect to the pedestal 18 and adjusting a pressingforce balance between the printing roller 33 and the backup roller 21 ina width direction of the film 12.

FIG. 4 are diagrams showing a structure of the unit moving mechanism 51,in which FIG. 4A is a schematic side view and FIG. 4B is a plan viewthereof. The unit moving mechanism 51 includes a rotary shaft 52disposed between the pedestal 18 and the mask forming unit 20, a drivingsource 53 for rotating the mask forming unit 20 about the rotary shaft52, and a guide portion 54 for guiding a movement of the mask formingunit 20 with respect to the pedestal 18. As shown in FIG. 4B, the rotaryshaft 52 is provided on one end side of the frame body 34 (one end sidein an axial direction of the printing roller 33), and the driving source53 is fixed on the pedestal 18 so that the other end side of the maskforming unit 20 can be driven forwardly and backwardly as indicated byan arrow S.

The driving source 53 is constituted of a fine feeding mechanism such asa stepping motor and a ball screw unit, and rotationally moves the framebody 34 about a point (rotary shaft 52) on the pedestal 18 in adirection indicated by an arrow C. It should be noted that a position atwhich the rotary shaft 52 is disposed is not limited to the exampleabove, but accuracy in rotation control becomes higher as a distancebetween the rotary shaft 52 (fulcrum) and the driving source 53(operating point) increases.

Next, descriptions will be given on an operation of the roll-to-rollvacuum vapor deposition apparatus 10 of this embodiment structured asdescribed above.

Inside the vacuum chamber 11 pressure-reduced to a predetermined vacuumdegree, the film 12 successively paid out from the payout roller 13 issubjected to the mask forming process and the vapor deposition processto thereafter be successively taken up by the take-up roller 15.

In the mask forming process, the mask pattern 25 in the form shown inFIG. 2A is printed on the deposition surface of the film 12 by the maskforming unit 20. The film 12 on which the mask pattern 25 has beenformed is wound around the can roller 14. It should be noted that, ifnecessary, processing for enhancing an adhesive force with respect tothe can roller 14, such as irradiation of charged particle beamsincluding electron beams onto the film 12, may be carried out. Bydepositing the evaporation material that has evaporated from theevaporation source 16 onto the deposition surface of the film 12, themetal layer 26 shown in FIG. 2B is formed. The film 12 on which themetal layer 26 has been deposited is taken up by the take-up roller 15via the guide roller.

Here, for forming the mask pattern 25 by the mask forming unit 20, apressing force balance between the printing roller 33 and the backuproller 21 nipping the traveling film 12, in the film width directionbecomes important. When the balance of the pressing force between thoserollers is poor, transfer accuracy of the oil pattern on one end sideand that on the other end side regarding the width direction of the film12 become different, to thus induce pattern breakage in a worst case.Such a problem is caused due to lowering of parallelism between shaftsof the printing roller 33 and the backup roller 21, so it is necessaryto highly-accurately adjust the shaft position of the printing roller 33with respect to the backup roller 21.

In this regard, because the mask forming unit 20 is disposed to berotatable with respect to the pedestal 18 that partially constitutes thevacuum chamber 11 in this embodiment, it is possible to adjust thepressing force while changing the shaft position of the printing roller33 with respect to the backup roller 21 by feed drive of the drivingsource 53, and highly-accurately adjust the parallelism between theshafts of those rolls 21 and 33. It should be noted that because thebackup roller 21 is constantly pressed toward the printing roller 33side by the biasing mechanism 41, a force of the printing roller 33 innipping the film 12 does not change at the time of adjustment of theshaft position.

Moreover, in this embodiment, because the pressing force between theprinting roller 33 and the backup roller 21 is adjusted through therelative movement of the entire mask forming unit 20 including theprinting roller 33 and the transfer roller 32 with respect to the vacuumchamber 11, individual adjustments of the printing roller 33 and thetransfer roller 32 are eliminated and a pressing force adjustment on aunit basis can be realized, thus achieving simplification of a structureand tasks and a reduction in work time.

Furthermore, it is also possible to structure the driving source 53 soas to be capable of being operated remotely from outside the vacuumchamber 11. In this case, the adjustment of the mask forming unit 20after exhaustion can be carried out with ease. For example, it alsobecomes possible to easily and speedily readjust the pressing forcebalance between the printing roller 33 and the backup roller 21 afterthe exhaustion, to thus improve productivity.

It should be noted that the frame body 34 of the mask forming unit 20 isdisposed to be movable with respect to the pedestal 18 or fixed only bythe rotary shaft 52, thus being hardly affected by the deformation ofthe vacuum chamber 11. Therefore, it is possible to suppress, even whenthe vacuum chamber 11 is exhausted after the adjustment of the maskforming unit 20 in the atmosphere, a fluctuation in the pressing forcebalance between the printing roller 33 and the backup roller 21.

Heretofore, the embodiment of the present invention has been described.However, the present invention is of course not limited thereto and canbe variously modified based on the technical idea of the presentinvention.

In the above embodiment, for example, the unit moving mechanism 51 has astructure in which the rotary shaft 52 is provided on one end side ofthe mask forming unit 20 and the driving source 53 is connected to theother end side. However, it is also possible that, instead, the drivingsource is provided on both end sides of the mask forming unit 20, andthe driving sources are driven and controlled to adjust the position ofthe mask forming unit 20, to thereby optimize the pressing force balancebetween the backup roller 21 and the printing roller 33.

Moreover, it is also possible to employ a form of control in which aprocess of checking the mask pattern 25 is added on a guide path of thefilm 12, and a result of the check is fed back to the unit movingmechanism 51 of the mask forming unit 20, to thus optimize the shaftposition of the printing roller 33.

It should be noted that in the above embodiment, descriptions have beengiven on the example where the metal layer is deposited by applying thevapor deposition method that uses the evaporation source 16 as thedepositing means. However, the present invention is of course notlimited thereto, and other deposition methods for depositing a metallayer or a nonmetal layer, such as a sputtering method or various CVDmethods are also applicable, and a depositing means such as a sputteringtarget can be employed as appropriate based on those deposition methods.

1. A roll-to-roll vacuum deposition apparatus comprising: a vacuumchamber; a traveling means for causing a film to travel inside thevacuum chamber; a depositing means for depositing a deposition materialon the traveling film; and a mask forming means disposed upstream of thedepositing means, for forming a mask pattern that defines a depositionarea of the deposition material on the film, wherein the mask formingmeans includes: a mask forming unit including a supply source for an oilfor forming the mask pattern, a first roller for holding the oilsupplied from the supply source at an outer circumference, and a secondroller for transferring the oil onto a deposition surface of the film asthe mask pattern, and a frame having a first end portion respectivelysupporting first ends of the first and second rollers and a second endportion respectively supporting second ends of the first and secondrollers; a backup roller for nipping the film with the second roller andcausing the film to come into pressure-contact with the second roller; abiasing mechanism for biasing the backup roller toward the secondroller; and a unit moving mechanism having a pedestal secured to thevacuum chamber and supporting the frame movably, a rotary shaft providedbetween the pedestal and the first end portion of the frame and adriving source fixed on the pedestal and configured to be capable ofmoving the second end portion of the frame toward the backup roller, theunit moving mechanism for rotationally moving a position of the maskforming unit about the rotary shaft with respect to the backup roller bythe driving source and adjusting a balance of a pressure contact forcebetween the second roller and the backup roller in a width direction ofthe film.
 2. The roll-to-roll vacuum deposition apparatus according toclaim 1, wherein the unit moving mechanism can be operated remotely fromoutside the vacuum chamber.